1. Field of the Invention
The present invention relates to an apparatus for cell observation and a method for cell collection using the same, and especially to an apparatus for cell observation, which is capable of achieving a simple, fast and accurate cell observation and a method for cell collection using the same.
2. Description of Related Art
A flow cytometry is currently the most widely used cell detection equipment in medical fields. The fluid system of a flow cytometry is based on a laminar flow or eddy-current to make the cells sequentially flow; and then the various parameters, such as the type, number and so on, of the cells flowing through the optical sensor are analyzed using light scattering and the fluorescent marker on the cell. In addition, a charge may be selectively applied to the passed cells, such that the passed cell will be deflected by action of the electromagnetic field and flow out from different exits for cell sorting. However, a flow cytometry is very expensive, bulky and complicated, and its operation and data analysis require intensive professional supervision, thereby limiting the universality.
Accordingly, in recent years, in the micro-electromechanical system (MEMS) field, a lot of researches with respect to the applications of the micro-fluid system have been conducted, intending to develop a small, fast, cheap and convenient chip for cell screening.
In the current studies, for example, numerous micro-column arrays are provided on the microchannel, which is further modified with EpCAM antibodies thereon for the specific bonding between the antibodies and the antigens, so as to achieve the circulating tumor cell (CTC) screening. However, this method cannot completely capture all the CTCs in the sample, and the modification of antibodies is required at the stage of chip production, so that the versatility for various types of cells is reduced. Another example is the combination of dielectrophoresis and field-flow fractionation, in which the electrically neutral cells are polarized by a special electrolyte to migrate toward the direction of a high-intensity or low-intensity electric field. The disadvantage of this method lies in the special electrolyte which may cause damage to the cell, and the sorting method based on cell size easily causes error separation. A further example is to modify a magnetic ball with the antibodies first, and a magnetic field is then used to fix the magnetic ball, such that the sample to be tested can flows slowly through for cell collection. However, in order to obtain a high separation efficiency, the cell flow needs to be controlled at a very low speed (only by about tens to hundreds of cells per second), and therefore it is extremely time-consuming and impractical in the practical application.
In view of the above, it is desirable to provide a small-size, low-cost, easy-to-use sorting apparatus for cell observation with low cell loss and high cell versatility, which can be used to provide a precise cell observation in the sample, thereby achieving the follow-up purposes of cell culture and experiment.